Determining a position may be accomplished in a variety of ways. Printed paper maps, information bulletin boards or signposts may be used to inform people of their whereabouts. Electronic devices may determine estimates of their locations by leveraging information that is available to them.
Electronic devices may determine estimates of their locations by receiving signals from positioning satellites, such as those comprised in the global positioning system, GPS, or GALILEO satellite constellations. Some devices are configured to use signals from satellites comprised in more than one such constellation to increase the accuracy of the estimated location compared to devices using satellites from only one constellation. Depending on the use case, locations may be determined with an accuracy of a few meters using satellite positioning.
Cellular communication devices may determine location estimates from an identity of a cell to which the cellular communication device is attached. Each cell may be configured with a cell identifier, which can be mapped to a location. The accuracy of this positioning method is dependent on the cell size and can vary from an accuracy of a few dozen meters to an accuracy of a few kilometers for larger cells.
Triangulation is a technique to determine a location based on receiving a plurality of signals and calculating their directions of arrival, DoA. Triangulation may result in a highly accurate position estimate in case the signals used are of a high quality. In some cases, a cellular communication device may triangulate its location using transmissions from a plurality of base stations. In such cases, triangulation may be employed in addition to, or alternatively to, using a cell identifier.
Consumer devices have in the past been furnished with pico projectors that may be used to project information from the device, such as a tablet device or cellular phone, to a wall. Pico projectors may be used to aid presentations given while travelling, for example on business trips when a separate, dedicated projector device is unavailable for use. For example in the year 2011, approximately 11 million pico projectors were sold to consumers comprised in mobile devices.